UNPARALLELED LTD is one of the leading manufacturers and suppliers of granite equal height blocks in China. With abundant experience, we warmly welcome you to buy advanced granite equal height blocks made in China here from our factory. We also accept custom orders.
Product overview
Granite equal height blocks are benchmark gauges for precision inspection and fixture setup. They are made of high-density black granite blanks through multiple aging processes and precision grinding. Featuring low thermal expansion coefficient, excellent vibration damping and good dimensional stability, granite equal height blocks are free from rust and stress deformation, unlike metal gauge blocks.
Fully stress-relieved after rough machining, these blocks maintain stable flatness, parallelism and height dimensions during long-term use. The set delivers high consistency in height among all pieces. Nano-level grinding is applied on working surfaces for superior surface finish and wear resistance, ideal for workpiece leveling, supporting and parallelism verification in constant-temperature metrology rooms.
All machining is completed in constant-temperature and vibration-isolated workshops. Tests are carried out with traceable imported metrology instruments to control parallelism, flatness and height tolerance complying with international metrology standards. UNPARALLELED® supplies standard sets of granite equal height blocks and accepts custom non-standard blocks in various sizes and accuracy grades. Widely used in CMM measurement, precision tooling, optical inspection and laboratory calibration, they serve customers from semiconductor, precision machinery, research institutes and metrology organizations.
| Raw Material | UNPARALLELED® dense black granite |
| density | 3100kg/m³ |
| Processing | Blank rough cutting → multi-cycle stress relief aging → fine grinding → nano-level surface lapping |
| Surface property | Wear-resistant, rust-free, non-magnetic, excellent vibration damping |
| Application | CMM inspection, fixture support, workpiece leveling, parallelism verification, laboratory calibration |
Quality Control
Features
Excellent material performance: Made of UNPARALLELED® dense black granite with density of 3100kg/m³ and thermal expansion coefficient ≤3e-6/℃. It delivers outstanding dimensional stability and is barely affected by temperature variation.
High wear resistance: Working surfaces are nano-lapped with high hardness. It resists abrasion after repeated long-term use and maintains reference accuracy steadily.
Non-magnetic & rust-free: The stone material will never rust and is non-magnetic, free from iron scrap adsorption, ideal for precision inspection and optical measurement.
Good vibration damping: High material damping absorbs micro-vibration and reduces measurement errors induced by vibration during testing.
Fully stress relieved: Raw blanks go through multiple static aging cycles to eliminate machining residual stress and prevent deformation in long service life.
High precision consistency: Blocks in one set feature excellent height uniformity. Flatness and parallelism reach micron or even nano level, meeting Grade 00 and Grade 0 metrology requirements.
Flexible customization: Apart from standard sets, non-standard sizes and multi-piece combinations can be customized to fit various fixtures and inspection machines.
Traceable inspection: Finished products are tested with CNAS traceable measuring instruments complying with DIN, ASME, JIS and GB standards. Inspection certificates are provided for each batch.
Maintenance & Protection
Storage environment: Store in dry, constant-temperature and dust-free metrology rooms, away from acid and corrosive substances. Do not place directly on hard metal tables. Use soft protective pads to avoid bumps and scratches on working surfaces.
Cleaning method: Wipe working surfaces with lint-free cloth dipped in anhydrous ethanol for daily maintenance. Never polish with sandpaper or metal scrapers, and avoid strong acid or alkaline cleaners.
Handling protection: Handle gently; do not drop or impact. Pack blocks separately for complete sets and add buffer separators between pieces to prevent mutual abrasion of working surfaces.
Operation rules: Do not apply overload pressure. Hammering workpieces on the blocks is prohibited. Avoid long-term single-point load to prevent hidden cracks inside the stone.
Precision re-verification: Regularly recheck flatness, parallelism and height dimensions with measuring instruments. If chipping or accuracy out-of-tolerance occurs due to collision, do not grind by yourself. Send back to the original factory for professional repair.
Long-term storage: For idle storage, apply special protective oil after cleaning and drying, put into matched dust-proof cases, store separately and keep away from metal tools.
Services
FAQ
Q1: What are the advantages of granite equal height blocks compared with steel ones?
A: Granite equal height blocks are non-magnetic and rust-free. They feature low thermal expansion coefficient and minimal dimensional deformation caused by temperature change. High material damping delivers excellent vibration damping and good long-term precision retention, ideal for high-precision metrology. Steel equal height blocks tend to rust, deform more under temperature variation and attract iron chips due to magnetism.
Q2: How to choose between Grade 00 and Grade 0?
A: Grade 00 has higher precision with tighter tolerance on flatness, parallelism and height. It is widely used for laboratory calibration, CMM matching and ultra-precision inspection. Grade 0 is suitable for standard precision tooling, workpiece leveling and production line inspection. Selection depends on equipment precision requirements and workshop environment.
Q3: Can you produce non-standard granite equal height blocks?
A: Yes. Besides standard sets, we accept custom dimensions and multi-piece combinations. Locating holes or mounting slots can be machined to match special fixtures.
Q4: Are granite equal height blocks easy to crack?
A: Qualified blanks are inspected for defects and processed with multi-cycle stress relief aging. They will not crack under normal use. However, granite is brittle. Heavy impact, dropping and overload pressure must be avoided, otherwise chipping or hidden internal cracks may occur.
Q5: What environment is required for use?
A: Constant-temperature, dry and low-dust metrology room is recommended. Keep away from acid, alkali and corrosive substances. Large temperature difference will cause temporary measurement error. Direct sunlight should also be avoided.
Q6: Can the block still be used if the working surface gets bumped or scratched?
A: Recheck precision for minor scratches. If chipping or deep scratches lead to out-of-tolerance accuracy, stop using it to prevent measurement error. Do not grind it by yourself. You can send it back to our factory for professional repair and re-inspection.
Q7: How many pieces are included in one standard set?
A: Typical sets contain 2, 3, 4 or 6 pieces. Custom multi-piece sets are available on request. All blocks within one set maintain consistent height.
Q8: Does each set come with inspection certificate?
A: Every finished set is delivered with CNAS traceable inspection certificate. Tests follow DIN, ASME, JIS, GB and other international metrology standards for customer laboratory verification and system audit.
Certificate
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